Use Gnuplot in VS Code: Syntax Highlighting & Run Tasks

Visual Studio Code makes a comfortable gnuplot editor: install a Gnuplot syntax extension from the Marketplace for highlighting, add a small task to run the current script with one shortcut, and keep the integrated terminal open for interactive plotting. gnuplot itself must be installed separately first.

Step 0: Install gnuplot Itself

VS Code only edits and launches scripts — the gnuplot program does the plotting. If gnuplot --version does not work in a terminal yet, follow the guide for your system: Windows, macOS, or Linux.

Step 1: Add Gnuplot Language Support

1. Open the Extensions view (Ctrl+Shift+X).
2. Search the Marketplace for “gnuplot” and install an extension that provides gnuplot syntax highlighting (language support for .gp and .plt files). Several community extensions offer this; pick one whose description mentions gnuplot syntax highlighting and check its recent update history.
3. Open any .gp script — keywords, comments, and strings should now be colourised and the language indicator in the status bar should read “gnuplot”.

Step 2: Add a Run Task

Create .vscode/tasks.json in your project folder with a task that runs the currently open script:

{
  "version": "2.0.0",
  "tasks": [
    {
      "label": "Run gnuplot script",
      "type": "shell",
      "command": "gnuplot",
      "args": ["-p", "${file}"],
      "problemMatcher": []
    }
  ]
}

Run it with Terminal → Run Task → Run gnuplot script. The -p flag keeps the plot window open after the script finishes.

Step 3: Verify in the Integrated Terminal

gnuplot --version
gnuplot -p -e "plot sin(x)"

The first line confirms VS Code’s terminal sees the same gnuplot as your system terminal; the second should pop up a sine plot. Save scripts with set terminal pngcairo and set output blocks when you want files instead of windows.

Common Pitfalls

• Task fails with “gnuplot not found” but the system terminal works: VS Code was already running when gnuplot was installed and inherited the old PATH. Restart VS Code completely.
• Plot window closes instantly: the -p (persist) flag is missing from the task arguments, or the script sets its own output file — both are fine, just check the generated PNG next to your script.

New to gnuplot itself? Start a script, then test commands interactively in the online terminal before wiring them into tasks.